It won't matter if you're obeying every other traffic law: Starting Tuesday, if you're talking on a hand-held mobile phone while driving in Maryland, the police will have the right to pull you over and ticket you.

The new law tightening the state's curb on cellphone use behind the wheel is one of hundreds that will take effect Tuesday as a result of General Assembly action this year. Among the others are high-profile measures banning the sale of some types of guns and repealing the death penalty.

Concerned about crashes caused by distracted drivers, lawmakers passed a hand-held cell phone ban in 2010 but made it a "secondary" offense, meaning an officer couldn't stop the vehicle without witnessing some other violation. This year proponents argued drivers had been given adequate notice. They persuaded the legislature to put more teeth in the law, making it a "primary" violation.

"It's really vital that the law is primary because drivers are very reluctant to put the phones down unless they think they're going to get a ticket," said Jonathan Adkins, spokesman for the Governors Highway Safety Association, which represents state highway safety offices.

John Wynn, 56, of Lutherville, a candy broker who drives some 40,000 miles a year, said he agrees with the intent of the law. He and his wife have been rear-ended in crashes caused by people who admitted to being on their phones.

"I do know that people get distracted. They can't multi-task, shifting gears, steering, on the phone watching the kids in the car," he said.

But Wynn wonders how enforceable the law — which also raises the fine for a violation from $40 to $75 — will be.

"They weren't able to enforce the secondary violations," Wynn said. "I'm just wondering if they are going to do something either at toll booths or on the side of the road and start nailing people with phones up to their ears."

Other new laws range from matters as narrow as the salaries of Orphans Court judges in Howard County to those as sweeping as life and death, as in the law abolishing capital punishment in Maryland.

Easily the most controversial legislation taking effect Tuesday — as measured by the outpouring of demonstrators in Annapolis – is the sweeping gun control bill passed in the wake of the mass killing last year at Sandy Hook Elementary School in Connecticut.

The law bans the sale of 45 types of long guns classified as assault rifles, along with handguns whose magazines accept more than 10 rounds. The law also requires licensing and fingerprinting of handgun buyers, and training for new handgun owners. It also bars gun ownership for more people with mental illnesses.

The measure set off a flurry of gun buying to beat the Oct. 1 deadline, resulting in a backlog in completing the background checks. State police announced they would waive the handgun license requirement for buyers who apply before Tuesday. The law faces a court challenge filed last week by gun rights advocates.

Another new law that stoked passions this year was the elimination of the death penalty. After many years of trying, opponents of capital punishment prevailed, with the help of Gov. Martin O'Malley and the NAACP, making Maryland the 18th state to end executions.

In addition to the stiffer cell phone law, drivers will now face a requirement that all passengers — even adults in back seats — wear seat belts.

John T. Kuo, head of the Motor Vehicle Administration, said while Maryland has a relatively high 91.1 percent seat belt compliance rate, it's important to reach that remaining 8.9 percent.

"In a crash, that back seat passenger, if you're unrestrained, becomes a projectile to the front seat passenger," he said.

The back seat provision will be a secondary offense, but the law also will double the maximum fine for violating the seat belt law from $25 to $50 and allow judges to impose court costs.

Montgomery County Police Capt. Thomas Didone, whose 15-year-old son was killed in a 2008 crash while riding in the back seat without a belt, said the new law could cost drivers $83 for every person in the vehicle who is unrestrained.

Didone said the new law also requires there be a seat belt or child safety seat for every person in a car. He said that could discourage teenagers from driving around in what police call "clown cars" — with more people packed into a car than it is designed to carry.

Another measure taking effect attempts to address the problem of "cyber-bullying" of minors by peers or adults over the Internet using social media. The legislation is known as "Grace's Law" after 15-year-old Grace McComas, a Howard County teen who committed suicide after repeated online harassment. The law makes bullying someone under 18 using a computer or smart phone a misdemeanor.

Maryland will take a small step toward less restrictive marijuana laws by allowing the drug's use to alleviate certain medical conditions. The law restricts such use to tightly regulated programs operated out of academic medical centers.

The state is also adopting its most comprehensive set of campaign finance reforms since the early 1990s. Among other provisions, the measure requires more timely reporting of contributions and seeks to close a loophole that has allowed some business owners to exceed donation limits many times over by using multiple corporations to give to candidates. It also increases donation limits for the first time in two decades to account for inflation.

Other laws that take effect Tuesday seek to protect newborn babies and users of swimming pools. One requires health professionals to tip off local social services departments when a newborn shows signs of exposure to illegal drugs or symptoms of fetal alcohol syndrome. The other tells publicly operated swimming pools to equip themselves with external defibrillators that can be used to shock a heart back into beating after a water rescue.

Legislators also stood up for another form of swimmer: the type with fins and razor-sharp teeth. In an effort to curb overfishing, a new law will ban the possession or sale of shark fins. Proponents contend that tens of millions of sharks are killed each year for their fins alone.

Tami Santelli, Maryland director of the Humane Society of the United States, said while sharks might not be the most appealing of animals, they play a crucial role.

"Their survival really impacts all kinds of species beneath them," she said. In the Chesapeake Bay, their decline has led to an abundance of cownose rays that has been devastating to the oyster population.

Baltimore Sun reporters Kevin Rector and Erin Cox contributed to this article.

Michael.dresser@baltsun.com

New laws on the books

These are among the hundreds of new Maryland laws taking effect Tuesday:

Cellphones

Drivers are already prohibited from using hand-held cellphones, but the new law lets police stop them for that offense alone.

Gun bill

Gov. Martin O'Malley's legislation bans the sale of certain guns classified as assault rifles and requires a license and fingerprints to purchase handguns. Gun rights groups have sued to block it.

Death penalty repeal

The law does not affect the five men now on death row, but no one else can be sentenced to death in Maryland.

Newborn drug exposure

Requires health care practitioners involved in delivering babies to report when newborns have been exposed to illegal drugs.

Defibrillators at pools

Requires public swimming pools to have defibrillators and staff trained to use them in medical emergencies.

Seat belts

Extends the requirement that adults wear seat belts to passengers in the rear seat and increases some fines for seat belt violations.

Shark fins

Prohibits possession, sale and distribution of shark fins in an attempt to protect the threatened species.

'Cyber-bullying'

Grace's Law, named for a Howard County teen who committed suicide after repeated online bullying, prohibits the use of social media to harass a minor.

Medical marijuana

Allows the limited distribution of marijuana by some academic medical centers.

Campaign finance reform

Closes a loophole that allowed some contributors to evade state limits by giving through many corporate entities.