Local police and other officials across the state are split on what may be the cause for the growing number of drug and narcotic charges.

"When you’re looking to any statistic where it’s drugs, it’s really difficult to pinpoint what causes the statistic to go up or down," Iowa City police Lt. Doug Hart said.

According to the 2011 Iowa City police annual report, drugs and narcotics charges have nearly doubled since 2007 — 626 charges last year, 332 in 2007.

"It could be increased drug problems, or it could be as simple as the fact that we have more officers working the street because we are in the process of replacing people who are retiring," Hart said.

Marijuana is the most popular substance in drug and narcotic charges locally and at the state level, Hart said, and Johnson County has also seen an increase in the number of heroin deaths.

Iowa City is not the only city in the state facing such an increase.

North Liberty Police Chief Jim Warkentin said police have recently seen an increase in the last year-and-a-half, despite an initial decrease after laws limiting the sale of Sudafed in 2005.

"Part of it is our population just keeps growing, and so we get more good people, and along with the good, you get some bad," he said.

In 2010, the North Liberty population was 13,374, an significant increase from 5,367 in 2000, according to the U.S. census.

Warkentin said the North Liberty police address growing drug problems by establishing long-term, rather than short-term, fixes. Those long-term solutions include creating more programs and activities for the community, he said.

"There are different things that the city does try to do for long-term," he said. "It’s not really aimed at drugs, it’s aimed at getting people and kids involved, hoping that it’ll keep them on a good path and they won’t turn to crime."

Iowa City police also work on drug enforcement by providing officers with training and assigning three officers to the street-crime unit.

Cedar Falls has seen a slight decrease from 96 charges in 2010 to 83 charges in 2011, yet one Cedar Falls police official noted that more durgs are being seized.

"In terms of seizures, the size of our seizures over the year has continued to rise," said Capt. Jeff Sitzmann.

New technology — such as global positioning systems and citizen aid — have contributed, he said.

"The biggest thing that we’re doing is a relationship with our citizens," he said. "We have to have a place to start and investigate."

These factors, he said, will contribute to enforcing drug laws.

"We’re always looking to get a bigger fish; we’re just trying to get to the top of the ladder, the source," Sitzmann said.