Kansas City, Mo. ? Saying “the best chapter of my life is closed,” U.S. Atty. Todd P. Graves said Friday that he was resigning after nearly five years of prosecuting federal cases in western Missouri.

Graves, 40, the former Platte County prosecutor, said his resignation would take effect March 24.

During a news conference, Graves said he planned to return to private practice and become more involved in politics, although he said he hadn’t decided whether he would run for office in the near future.

“I have the greatest job a practicing lawyer anywhere could have,” he said, surrounded by his top assistant U.S. attorneys and staff. “But I’m also someone who thinks the next thing is going to be the best thing, the greatest thing.”

Graves said he had been planning his exit almost from the day he was confirmed by the U.S. Senate in October 2001, given that U.S. attorneys rarely survive the changeover of presidential administrations.

“Being a political appointee in a job like this is always going to end in a resignation – if you’re lucky,” he said with a laugh.

He said he set a number of goals and had met most of them.

Under his watch, criminal prosecutions have increased 34 percent in Missouri’s Western District, his office is responsible for about 10 percent of all inmates now sitting on death row in the federal system, and the office has become much more involved in computer crimes and child pornography cases.

The office prosecuted 42 child exploitation cases in 2005, the sixth highest in the nation and the most for any district east of the Rocky Mountains.

“I think that should be on my tombstone: that we moved this office into the computer age as soon as we could,” he said.