NAPOLEONVILLE - A former Assumption Parish sheriff’s lieutenant will serve five years in prison, followed by five years of supervised probation, for tampering with evidence in hundreds of narcotics cases, 23rd Judicial District Judge Jane Triche-Milazzo ruled on Thursday.

Louis Lambert, 46, of Labadieville, who oversaw the Sheriff’s Office evidence vault, pleaded guilty in May to more than 400 charges, including 336 counts of malfeasance and 102 other counts that include drug, weapons and theft charges.

Though Triche-Milazzo imposed a prison term for all 438 counts, the sentences will run concurrently, not back-to-back. Lambert was assigned the most time, 10 years, for illegal possession of a firearm. Five years of that sentence was suspended, leaving five years to be served with no possibility of parole.

“We’re disappointed,” said District Attorney Ricky Babin, “but we respect the court’s decision. We had to spend time tracking down defense attorneys in 500-plus cases. We were required to notify each one that may have been affected.”

Prosecutors said in a May news release that very few cases had to be dismissed because of the tampering.

The court also imposed more than $69,000 in fines, according to the ruling, and ordered Lambert to pay nearly $22,000 in restitution to Babin’s office, Louisiana State Police and the Sheriff’s Office for expenses incurred as a result of the case.

Lambert removed drugs and other items from evidence to support a substance abuse problem, according to court documents.

Last year, altered drug evidence discovered in one case triggered a three-month investigation that uncovered the rest.

Lambert attributes his addiction in part to the time he spent in combat while serving with the U.S. Army, and a serious car crash in 1999 that left him bedridden for 13 months, the ruling stated. Lambert enrolled in a rehabilitation center just after an investigation opened into allegations of official misconduct against Lambert.

Lambert will serve his time at the Martin L. Forcht Jr. Clinical Treatment Center Unit in Caddo Parish, run by the Louisiana Department of Corrections.